1. Field of the Invention
The present invention relates to a process for producing a cephalosporanic acid derivative, and more particularly to a process for producing a cephalosporanic acid derivative from a cephalosporanic phosphoramide.
2. Description of the Prior Art
The cephalosporanic acid derivative of the formula (I) can be obtained, as disclosed in U.S. Pat. No. 3,275,626, by conversion of a 1-oxide derivative of 6-acylamidopenicillin to obtain the corresponding 7-acylamidocephalosporin derivative followed by a deacylation of the resulting 7-acylamidocephalosporin derivative, as disclosed in U.S. Pat. No. 3,549,628. The deacylation, however, gives rise to many problems which render it difficult to carry out the acylation on an industrial scale, that is, it is essential to isolate and purify the 7-acylamidocephalosporin because the yield of the desired compound of the formula (I) is remarkably influenced by the purity of the 7-acylamidocephalosporin and, in addition, the reaction system must strictly be controlled so as to maintain anhydrous conditions.